Quantum Dot White LEDs: Researchers Find Record Efficiency With These LEDs

Quantum dot white LEDs? Sounds like something out of a sci-fi movie! But these are actually a real thing, and they are a ground-breaking discovery in LED technology. Researchers at Koç University in Turkey have discovered a new way to create quantum dot LEDs using a different approach that achieves a 105 lumens per watt, and could potentially achieve 200 lumens per watt.

New Quantum Dot White LED Technology Explained

Sedat Nizamoglu, head researcher at the Koç University in Turkey, explains that these quantum dots are more efficient than others because of a nano-material base produced using a solution (liquid) rather than a solid. This means higher efficiency, and lower cost.

“Our new LEDs reached a higher efficiency level than other quantum dot-based white LEDs. The synthesis and fabrication methods for making the quantum dots and the new LEDs are easy, inexpensive and applicable for mass production.” – Sedat Nizamoglu, Koç University

To create this white light, the research team uses blue LEDs in a flexible lens injected with the solution of nano-sized particles of semiconducting materials (quantum dots). In turn, the blue light allows the quantum dots to release green and red light, which combines with the blue light to produce white.

The researchers experimented with more than 300 synthesis reactions when creating their quantum dots so that they emitted at different colors with high efficiency.

Quantum Dot White LEDs vs. Regular White LEDs

How is this different than today’s white-colored LED bulbs that we see in our homes, offices, stores, etc? The white light you see emitted from LED bulbs is produced by blue LEDs covered with a phosphor-based coating that has a yellowish coloring. When the blue light is emitted with the yellow phosphor-based coating, it produces a white coloring.

Phosphors have low conversion efficiencies, and have a broad range of wavelengths (that emit colors from blue to red). Quantum dots have high conversion efficiencies and low wavelengths, making them easier for creating higher energy efficiency, and a more precise white color temperature. 

The Future Is Quantum Dots For LEDs

The researchers’ liquid technology for creating quantum dots proves that white LEDs can achieve an efficiency that is double that of LEDs created with quantum dots in solid forms. According to Nizamoglu, this means that if people were to replace their regular lighting with LEDs that have an efficiency of 200 lumens per watt, global electricity consumption for lighting would decrease by more than half.

“Quantum dots hold great promise for efficient lighting applications. There is still significant room for technology development that would generate more efficient approaches to lighting.” – Sedat Nizamoglu, Koç University

Sources:

https://www.osa.org/en-us/about_osa/newsroom/news_releases/2018/quantum_dot_white_leds_achieve_record_efficiency/

https://www.osa-opn.org/home/newsroom/2018/july/bright_white_leds_with_a_liquid_qd_center/

http://www.physicscentral.com/buzz/blog/index.cfm?postid